Don’t be silly. You’re leaping from nitpicking to a blanket assumption that the author is completely clueless. Elsewhere in the article: The Euler equations ar

Don’t be silly. You’re leaping from nitpicking to a blanket assumption that the author is completely clueless. Elsewhere in the article: The Euler equations are not a literal description of a real-world fluid. They include several nonphysical assumptions. The author does in fact know about the subject.